Document
DATA SHEET
BiCMOS INTEGRATED CIRCUIT
µ PC1935
DC-DC CONVERTER CONTROL IC
DESCRIPTION
The µ PC1935 is a low-voltage input DC-DC converter control IC that can configure a three-output (step-up × 2, inverted output × 1) DC-DC converter at an input voltage of 3, 3.3, or 5 V. Because of its wide operating voltage range, this IC can also be used to control DC-DC converters using an AC adapter for input.
FEATURES
• Low supply voltage: 2.5 V (MIN.) • Operating voltage range: 2.5 to 20 V (breakdown voltage: 30 V) • Can control three output channels. • Timer latch circuit for short-circuit protection. • Ceramic capacitor with low capacitance (0.1 µ F) can be used for short-circuit protection. • Dead times of channels 2 (step-up) and 3 (inverted output) can be set from external resistors. Dead time of channel 1 (step-up) is internally fixed to 85 %. • Soft start of each channel can be set independently. • Each channel can be turned ON/OFF independently.
ORDERING INFORMATION
Part Number Package 16-pin plastic TSSOP (5.72 mm (225))
µ PC1935GR
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Document No. G13418EJ3V0DS00 (3rd edition) Date Published March 2000 NS CP (K) Printed in Japan
The mark 5 shows major revised points. 1998
µ PC1935
BLOCK DIAGRAM
Channel 3: for inversion DTC3 16 Il3 15 FB3 14 OUT3 13 DTC2 12 Il2 11 Channel 2: for step-up FB2 10 OUT2 9
– + – – +
– + + + –
Internal fixed voltage
Internal fixed voltage
Soft start select switch
+ – +
Internal fixed voltage
–
Reference voltage section
Oscillation section
Timer latch for short-circuit protection section
+
Internal fixed voltage 6 7 FB1 Channel 1: for step-up 8 OUT1
1 VCC
2 VREF
3 RT
4 GND
5 DLY
II1
2
Data Sheet G13418EJ3V0DS00
µ PC1935
PIN CONFIGURATION (Top view)
16-pin plastic TSSOP (5.72 mm (225)) • µ PC1935GR
VCC VREF RT GND DLY II1 FB1 OUT1
1 2 3 4 5 6 7 8
16 15 14 13 12 11 10 9
DTC3 II3 FB3 OUT3 DTC2 II2 FB2 OUT2
PIN FUNCTIONS
Pin No. 1 2 3 4 5 Symbol VCC VREF RT GND DLY Power supply Reference voltage output Frequency setting resistor connection Ground Short-circuit protection/channel 1 soft start capacitor connection 6 7 8 II1 FB1 OUT1 Channel 1 error amplifier inverted input Channel 1 error amplifier output Channel 1 open-drain output 14 15 16 FB3 II3 DTC3 Channel 3 error amplifier output Channel 3 error amplifier inverted input Channel 3 dead time setting Function Pin No. 9 10 11 12 13 Symbol OUT2 FB2 II2 DTC2 OUT3 Function Channel 2 open-drain output Channel 2 error amplifier output Channel 2 error amplifier inverted input Channel 2 dead time setting Channel 3 open-drain output
Data Sheet G13418EJ3V0DS00
3
µ PC1935
CONTENTS 1. ELECTRICAL SPECIFICATIONS ...............................................................